Cisco 1603R User Manual page 71

Dial-on-Demand Routing Over ISDN
To place calls on the ISDN interface, you must configure it with dial-on-demand routing
(DDR). See the chapter "Configuring DDR" in the Wide-Area Networking Configuration
Guide publication for detailed information about DDR.
Bandwidth on Demand and Dial Backup over ISDN
See the chapter "Configuring DDR" in the Wide-Area Networking Configuration Guide
publication for detailed information about bandwidth on demand and dial backup.
Dial-on-Demand Routing Over ISDN
Configuring the ISDN Line B-7